<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>让Fido减减肥！</title>
</head>
<body>
  <script>
      fido  = {
          name:"fido",
          weight:48,
          breed:"Mixed",
          loves:"walks"
      }
      function loseWeight(dog, amount) {
          dog.weight = dog.weight - amount;
      }

      loseWeight(fido, 10);
      console.log(fido.name + " now weighs " + fido.weight);
  </script>
</body>
</html>